标题: 谁知道这道题准确的答案是什么？ [打印本页] 作者: 何小媛159753 时间: 2011-8-4 08:23 标题: 谁知道这道题准确的答案是什么？ 8. george: some scientists say that global warming will occur because people are releasing large amounts of carbon dioxide into the atmosphere by burning trees and fossil fuels. we can see, though, that the predicted warming is occurring already. in the middle of last winter, we had a month of springlike weather in our area, and this fall, because of unusually mild temperatures, the leaves on our town抯 trees were three weeks late in turning color. which one of the following would it be most relevant to investigate in evaluating the conclusion of george抯 argument? (a) whether carbon dioxide is the only cause of global warming (b) when leaves on the trees in the town usually change color (c) what proportion of global emissions of carbon dioxide is due to the burning of trees by humans (d) whether air pollution is causing some trees in the are to lose their leaves (e) whether unusually warm weather is occurring elsewhere on the globe more frequently than before作者: sdcar2010 时间: 2011-8-4 08:41
EEEEEEEEEEEEEEEEEEEEEe作者: 何小媛159753 时间: 2011-8-4 09:09
晓得了，谢谢~